Introduction: The term myelopathy refers to any disorder leading to loss of function of spinal cord tracts. In practice, most physicians diagnose myelopathy based on objective signs of hyperreflexia, ataxia and pathological spinal reflexes in the setting of radiographic spinal cord pathology. Myelopathy, though, may present with loss of pain and temperature sensation from compression of the anterolateral spinothalamic tract without involvement of other spinal cord tracts. The purpose of this study is to identify and describe patients who present with radiographically documented spinal cord compression causing dysfunction of the anterior spinothalamic tracts.
Methods: This study is a retrospective review of patients with radiographic documentation of cervical spinal cord compression and loss of pain and/or temperature sensation below the level of the lesion. Patients who exhibited signs of corticospinal tract dysfunction were excluded. Pertinent preoperative and postoperative data were collected.
Results: Six individuals were identified as having loss of sensation to pain and/or temperature below the level of anterior spinal cord compression. In all cases, the compression was due to a cervical herniated disc. The presenting complaint was radiculopathy in five of six patients while one presented with only loss of pain and temperature. No patient had hyperreflexia, ataxia of gait, finger clumsiness or deficit to light touch. No patient had abnormal neurophysiology. All patients underwent an anterior cervical discectomy and fusion
Conclusions: Compression of the anterolateral spinothalamic tract can lead to dysfunction of pain and temperature sensation without causing typical signs of myelopathy. The most common cause is a large herniated cervical disc with or without spondylytic compression of the anterolateral spinal cord. If clinicians require spasticity, hyperreflexia, clonus and pathological reflexes for the diagnosis of myelopathy, many patients with anterior sensory myelopathy will be missed or have delay in treatment
Patient Care: Surgical intervention is often delayed for patients with cervical radiculopathy to allow for more attempts at conservative treatment. Conservative measures are contra-indicated in patients with cervical myelopathy. We present a series of patients who have a form of myelopathy that might be overlooked or missed because anterior sensory myelopathy lacks the usual signs of myelopathy. Recognition of this syndrome will hopefully prevent delay in surgical intervention.
Learning Objectives: By the conclusion of this session, participants should be able to: 1) Describe the cross-sectional anatomy of the cervical spinal cord, 2) Describe the relationship of herniated cervical discs to spinal cord tracts, 3) Recognize the syndrome of anterior sensory myelopathy.